/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1994, 95, 96, 97, 98, 99, 2003 by Ralf Baechle
* Copyright (C) 1996 by Paul M. Antoine
* Copyright (C) 1999 Silicon Graphics
* Kevin D. Kissell, kevink@mips.org and Carsten Langgaard, carstenl@mips.com
* Copyright (C) 2000 MIPS Technologies, Inc.
*/
#ifndef _ASM_SYSTEM_H
#define _ASM_SYSTEM_H
#include <linux/config.h>
#include <linux/types.h>
#include <asm/addrspace.h>
#include <asm/cpu-features.h>
#include <asm/ptrace.h>
#include <asm/war.h>
#include <asm/interrupt.h>
/*
* read_barrier_depends - Flush all pending reads that subsequents reads
* depend on.
*
* No data-dependent reads from memory-like regions are ever reordered
* over this barrier. All reads preceding this primitive are guaranteed
* to access memory (but not necessarily other CPUs' caches) before any
* reads following this primitive that depend on the data return by
* any of the preceding reads. This primitive is much lighter weight than
* rmb() on most CPUs, and is never heavier weight than is
* rmb().
*
* These ordering constraints are respected by both the local CPU
* and the compiler.
*
* Ordering is not guaranteed by anything other than these primitives,
* not even by data dependencies. See the documentation for
* memory_barrier() for examples and URLs to more information.
*
* For example, the following code would force ordering (the initial
* value of "a" is zero, "b" is one, and "p" is "&a"):
*
* <programlisting>
* CPU 0 CPU 1
*
* b = 2;
* memory_barrier();
* p = &b; q = p;
* read_barrier_depends();
* d = *q;
* </programlisting>
*
* because the read of "*q" depends on the read of "p" and these
* two reads are separated by a read_barrier_depends(). However,
* the following code, with the same initial values for "a" and "b":
*
* <programlisting>
* CPU 0 CPU 1
*
* a = 2;
* memory_barrier();
* b = 3; y = b;
* read_barrier_depends();
* x = a;
* </programlisting>
*
* does not enforce ordering, since there is no data dependency between
* the read of "a" and the read of "b". Therefore, on some CPUs, such
* as Alpha, "y" could be set to 3 and "x" to 0. Use rmb()
* in cases like thiswhere there are no data dependencies.
*/
#define read_barrier_depends() do { } while(0)
#ifdef CONFIG_CPU_HAS_SYNC
#define __sync() \
__asm__ __volatile__( \
".set push\n\t" \
".set noreorder\n\t" \
".set mips2\n\t" \
"sync\n\t" \
".set pop" \
: /* no output */ \
: /* no input */ \
: "memory")
#else
#define __sync() do { } while(0)
#endif
#define __fast_iob() \
__asm__ __volatile__( \
".set push\n\t" \
".set noreorder\n\t" \
"lw $0,%0\n\t" \
"nop\n\t" \
".set pop" \
: /* no output */ \
: "m" (*(int *)CKSEG1) \
: "memory")
#define fast_wmb() __sync()
#define fast_rmb() __sync()
#define fast_mb() __sync()
#define fast_iob() \
do { \
__sync(); \
__fast_iob(); \
} while (0)
#ifdef CONFIG_CPU_HAS_WB
#include <asm/wbflush.h>
#define wmb() fast_wmb()
#define rmb() fast_rmb()
#define mb() wbflush()
#define iob() wbflush()
#else /* !CONFIG_CPU_HAS_WB */
#define wmb() fast_wmb()
#define rmb() fast_rmb()
#define mb() fast_mb()
#define iob() fast_iob()
#endif /* !CONFIG_CPU_HAS_WB */
#ifdef CONFIG_SMP
#define smp_mb() mb()
#define smp_rmb() rmb()
#define smp_wmb() wmb()
#define smp_read_barrier_depends() read_barrier_depends()
#else
#define smp_mb() barrier()
#define smp_rmb() barrier()
#define smp_wmb() barrier()
#define smp_read_barrier_depends() do { } while(0)
#endif
#define set_mb(var, value) \
do { var = value; mb(); } while (0)
#define set_wmb(var, value) \
do { var = value; wmb(); } while (0)
/*
* switch_to(n) should switch tasks to task nr n, first
* checking that n isn't the current task, in which case it does nothing.
*/
extern asmlinkage void *resume(void *last, void *next, void *next_ti);
struct task_struct;
#define switch_to(prev,next,last) \
do { \
(last) = resume(prev, next, next->thread_info); \
} while(0)
#define ROT_IN_PIECES \
" .set noreorder \n" \
" .set reorder \n"
static inline unsigned long __xchg_u32(volatile int * m, unsigned int val)
{
__u32 retval;
if (cpu_has_llsc && R10000_LLSC_WAR) {
unsigned long dummy;
__asm__ __volatile__(
"1: ll %0, %3 # xchg_u32 \n"
" move %2, %z4 \n"
" sc %2, %1 \n"
" beqzl %2, 1b \n"
ROT_IN_PIECES
#ifdef CONFIG_SMP
" sync \n"
#endif
: "=&r" (retval), "=m" (*m), "=&r" (dummy)
: "R" (*m), "Jr" (val)
: "memory");
} else if (cpu_has_llsc) {
unsigned long dummy;
__asm__ __volatile__(
"1: ll %0, %3 # xchg_u32 \n"
" move %2, %z4 \n"
" sc %2, %1 \n"
" beqz %2, 1b \n"
#ifdef CONFIG_SMP
" sync \n"
#endif
: "=&r" (retval), "=m" (*m), "=&r" (dummy)
: "R" (*m), "Jr" (val)
: "memory");
} else {
unsigned long flags;
local_irq_save(flags);
retval = *m;
*m = val;
local_irq_restore(flags); /* implies memory barrier */
}
return retval;
}
#ifdef CONFIG_64BIT
static inline __u64 __xchg_u64(volatile __u64 * m, __u64 val)
{
__u64 retval;
if (cpu_has_llsc && R10000_LLSC_WAR) {
unsigned long dummy;
__asm__ __volatile__(
"1: lld %0, %3 # xchg_u64 \n"
" move %2, %z4 \n"
" scd %2, %1 \n"
" beqzl %2, 1b \n"
ROT_IN_PIECES
#ifdef CONFIG_SMP
" sync \n"
#endif
: "=&r" (retval), "=m" (*m), "=&r" (dummy)
: "R" (*m), "Jr" (val)
: "memory");
} else if (cpu_has_llsc) {
unsigned long dummy;
__asm__ __volatile__(
"1: lld %0, %3 # xchg_u64 \n"
" move %2, %z4 \n"
" scd %2, %1 \n"
" beqz %2, 1b \n"
#ifdef CONFIG_SMP
" sync \n"
#endif
: "=&r" (retval), "=m" (*m), "=&r" (dummy)
: "R" (*m), "Jr" (val)
: "memory");
} else {
unsigned long flags;
local_irq_save(flags);
retval = *m;
*m = val;
local_irq_restore(flags); /* implies memory barrier */
}
return retval;
}
#else
extern __u64 __xchg_u64_unsupported_on_32bit_kernels(volatile __u64 * m, __u64 val);
#define __xchg_u64 __xchg_u64_unsupported_on_32bit_kernels
#endif
/* This function doesn't exist, so you'll get a linker error
if something tries to do an invalid xchg(). */
extern void __xchg_called_with_bad_pointer(void);
static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size)
{
switch (size) {
case 4:
return __xchg_u32(ptr, x);
case 8:
return __xchg_u64(ptr, x);
}
__xchg_called_with_bad_pointer();
return x;
}
#define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
#define tas(ptr) (xchg((ptr),1))
#define __HAVE_ARCH_CMPXCHG 1
static inline unsigned long __cmpxchg_u32(volatile int * m, unsigned long old,
unsigned long new)
{
__u32 retval;
if (cpu_has_llsc && R10000_LLSC_WAR) {
__asm__ __volatile__(
" .set noat \n"
"1: ll %0, %2 # __cmpxchg_u32 \n"
" bne %0, %z3, 2f \n"
" move $1, %z4 \n"
" sc $1, %1 \n"
" beqzl $1, 1b \n"
ROT_IN_PIECES
#ifdef CONFIG_SMP
" sync \n"
#endif
"2: \n"
" .set at \n"
: "=&r" (retval), "=m" (*m)
: "R" (*m), "Jr" (old), "Jr" (new)
: "memory");
} else if (cpu_has_llsc) {
__asm__ __volatile__(
" .set noat \n"
"1: ll %0, %2 # __cmpxchg_u32 \n"
" bne %0, %z3, 2f \n"
" move $1, %z4 \n"
" sc $1, %1 \n"
" beqz $1, 1b \n"
#ifdef CONFIG_SMP
" sync \n"
#endif
"2: \n"
" .set at \n"
: "=&r" (retval), "=m" (*m)
: "R" (*m), "Jr" (old), "Jr" (new)
: "memory");
} else {
unsigned long flags;
local_irq_save(flags);
retval = *m;
if (retval == old)
*m = new;
local_irq_restore(flags); /* implies memory barrier */
}
return retval;
}
#ifdef CONFIG_64BIT
static inline unsigned long __cmpxchg_u64(volatile int * m, unsigned long old,
unsigned long new)
{
__u64 retval;
if (cpu_has_llsc) {
__asm__ __volatile__(
" .set noat \n"
"1: lld %0, %2 # __cmpxchg_u64 \n"
" bne %0, %z3, 2f \n"
" move $1, %z4 \n"
" scd $1, %1 \n"
" beqzl $1, 1b \n"
ROT_IN_PIECES
#ifdef CONFIG_SMP
" sync \n"
#endif
"2: \n"
" .set at \n"
: "=&r" (retval), "=m" (*m)
: "R" (*m), "Jr" (old), "Jr" (new)
: "memory");
} else if (cpu_has_llsc) {
__asm__ __volatile__(
" .set noat \n"
"1: lld %0, %2 # __cmpxchg_u64 \n"
" bne %0, %z3, 2f \n"
" move $1, %z4 \n"
" scd $1, %1 \n"
" beqz $1, 1b \n"
#ifdef CONFIG_SMP
" sync \n"
#endif
"2: \n"
" .set at \n"
: "=&r" (retval), "=m" (*m)
: "R" (*m), "Jr" (old), "Jr" (new)
: "memory");
} else {
unsigned long flags;
local_irq_save(flags);
retval = *m;
if (retval == old)
*m = new;
local_irq_restore(flags); /* implies memory barrier */
}
return retval;
}
#else
extern unsigned long __cmpxchg_u64_unsupported_on_32bit_kernels(
volatile int * m, unsigned long old, unsigned long new);
#define __cmpxchg_u64 __cmpxchg_u64_unsupported_on_32bit_kernels
#endif
/* This function doesn't exist, so you'll get a linker error
if something tries to do an invalid cmpxchg(). */
extern void __cmpxchg_called_with_bad_pointer(void);
static inline unsigned long __cmpxchg(volatile void * ptr, unsigned long old,
unsigned long new, int size)
{
switch (size) {
case 4:
return __cmpxchg_u32(ptr, old, new);
case 8:
return __cmpxchg_u64(ptr, old, new);
}
__cmpxchg_called_with_bad_pointer();
return old;
}
#define cmpxchg(ptr,old,new) ((__typeof__(*(ptr)))__cmpxchg((ptr), (unsigned long)(old), (unsigned long)(new),sizeof(*(ptr))))
extern void *set_except_vector(int n, void *addr);
extern void per_cpu_trap_init(void);
extern NORET_TYPE void __die(const char *, struct pt_regs *, const char *file,
const char *func, unsigned long line);
extern void __die_if_kernel(const char *, struct pt_regs *, const char *file,
const char *func, unsigned long line);
#define die(msg, regs) \
__die(msg, regs, __FILE__ ":", __FUNCTION__, __LINE__)
#define die_if_kernel(msg, regs) \
__die_if_kernel(msg, regs, __FILE__ ":", __FUNCTION__, __LINE__)
extern int stop_a_enabled;
/*
* See include/asm-ia64/system.h; prevents deadlock on SMP
* systems.
*/
#define __ARCH_WANT_UNLOCKED_CTXSW
#define arch_align_stack(x) (x)
#endif /* _ASM_SYSTEM_H */
